Xtreme Power X90-5S vs Mitsubishi 9900B
A 50–350 kW modular 480V UPS comparison — the hot-swappable, high-density X90-5S against the Mitsubishi 9900B, drawn at the 280 kW / 300 kW operating point. The X90-5S is a scalable, modular online double-conversion UPS that protects critical data and equipment, available from 50 kW to 350 kW.
Integrated hot-swap modular vs. conventional modular
The Xtreme Power Conversion X90-5S is a scalable, modular online double-conversion 480V UPS that efficiently protects critical data and equipment from power problems, available in capacities from 50 kW to 350 kW.
The Mitsubishi 9900B is an online double-conversion UPS deployed across data-center and facility environments. This comparison is drawn at the X90-5S 280 kW configuration against the Mitsubishi 9900B 300 kW.
At this operating point the 9900B starts 20 kW higher, but the X90-5S scales in-cabinet to 350 kW (or to 280 kW N+1) by adding a 70 kW module, and differs in power-module serviceability, weight, footprint, and ECO-mode efficiency, as compared below.
How the two architectures differ
The Xtreme Power X90-5S is a scalable, modular online double-conversion 480V UPS built from hot-swappable 50 kW and 70 kW power modules, scaling from 50 kW to 350 kW within a single high-density cabinet. Power modules can be added or replaced while the system continues to protect the load.
Because power and battery modules are front-accessible and hot-swappable, capacity expansion and module service do not require transferring the load to unprotected utility power — an architectural difference that affects serviceability, uptime risk, and electrical-room planning.
Per the supplied comparison, the 9900B power modules are not hot-swappable, and adding capacity or N+1 redundancy requires an additional whole UPS cabinet plus a tie cabinet. The X90-5S scales from 280 kW to 350 kW — or to 280 kW N+1 redundancy — by adding a 3U 70 kW power module within the same cabinet, with no additional footprint.
X90-5S vs Mitsubishi 9900B
| Feature | Xtreme Power X90-5S | Mitsubishi 9900B | Advantage |
|---|---|---|---|
| Capacity (kW) | 280 kW | 300 kW | The Mitsubishi 9900B initial capacity is 20 kW higher than the X90-5S at 280 kW. |
| Upgradeability / scalable | Yes — upgradeable to 350 kW, or to 280 kW N+1 | No | The X90-5S 280 kW capacity can be upgraded to 350 kW, or configured as 280 kW N+1 redundant, simply by adding a 3U 70 kW power module — no additional footprint required. Adding capacity or redundancy to the 9900B requires an additional whole UPS cabinet and tie cabinet. |
| Hot-swappable power modules | Yes — hot-swap power modules | No | X90-5S power modules can be added or replaced at any time without powering the system down. The 9900B does not offer hot-swappable modules. |
| Efficiency | Up to 99% ECO mode or 96.5% online mode | Up to 96.2% online mode | The X90-5S and 9900B both offer industry-leading online efficiency; the X90-5S additionally provides an ECO mode up to 99%. |
| Footprint | 31.5″W × 42″D × 79″H (9.2 sq ft) | 55.1″W × 32.7″D × 80.7″H (12.5 sq ft) | The Mitsubishi 9900B is about 24″ wider and occupies a roughly 36% larger footprint than the X90-5S. |
| Weight | 1,203 lbs | 2,360 lbs | The X90-5S is roughly half the weight of the Mitsubishi 9900B. |
| Power density | Up to 38 kW per sq ft | Up to 24 kW per sq ft | The X90-5S delivers much higher kW per square foot than the 9900B. |
| Warranty | 2 years on-site with factory start-up | 1 year on-site with factory start-up | Xtreme Power’s standard warranty covers 2 years versus 1 year for the 9900B. |
Mitsubishi 9900B figures are shown as supplied and are unverified; confirm against current manufacturer documentation. X90-5S figures per the X90-5S datasheet.
Where the X90-5S leads
- Scales in-cabinet past the 9900B. The 280 kW X90-5S upgrades to 350 kW, or to 280 kW N+1, by adding a 70 kW module with no added footprint. The 9900B requires an additional whole UPS and tie cabinet.
- No-downtime module service. Power modules are hot-swappable; the 9900B does not offer hot-swappable modules.
- Roughly half the weight. 1,203 lbs versus 2,360 lbs.
- 36% smaller footprint, higher density. 9.2 sq ft versus 12.5 sq ft (about 24″ narrower), at up to 38 kW/sq ft versus up to 24 kW/sq ft.
- ECO efficiency up to 99%. Both platforms post industry-leading online efficiency (X90-5S 96.5% vs 9900B 96.2%); the X90-5S adds an ECO mode up to 99%.
- Longer standard coverage. 2-year on-site parts & labor warranty with factory start-up, versus 1 year.
Specification summary
| Parameter | Xtreme Power X90-5S | Mitsubishi 9900B |
|---|---|---|
| Compared rating | 280 kW (upgradeable to 350 kW / N+1) | 300 kW |
| Topology | Online double conversion | Online double conversion |
| Input / output voltage | 480 V three-phase | 480 V three-phase |
| Efficiency | Up to 96.5% online / 99% ECO | Up to 96.2% online |
| Power-module service | Hot-swappable (no system power-down) | Not hot-swappable |
| Capacity upgrade | In-cabinet to 350 kW or N+1 (add 70 kW modules) | Additional UPS cabinet + tie cabinet required |
| Footprint | 9.2 sq ft (31.5 × 42 × 79 in) | 12.5 sq ft (55.1 × 32.7 × 80.7 in) |
| Weight | 1,203 lbs | 2,360 lbs |
| Power density | Up to 38 kW/sq ft | Up to 24 kW/sq ft |
| Warranty (standard) | 2 years on-site + factory start-up | 1 year on-site + factory start-up |
Detailed electrical specifications vary by configuration.
Where planners evaluate the X90-5S
Infrastructure planners frequently evaluate the X90-5S where:
- Phased capacity growth from 280 kW to 350 kW, or N+1 redundancy, without added footprint
- Weight- or floor-loading-constrained installations
- Footprint- and density-constrained electrical rooms
- Deployments that cannot transfer the load to utility power for module expansion or service
- Projects standardizing on a longer parts & labor warranty with factory start-up
Compare the X90-5S with other modular UPS platforms
Engineering planning support
Xtreme Power Conversion supports facility engineers, consultants, and system integrators with modular UPS architecture evaluation, electrical-room deployment planning, capacity scaling strategy, and infrastructure upgrade assessment.